1. Field of the Invention
The present invention relates to a liquid liquid process on a substrate, such as a semiconductor processing apparatus for performing a predetermined wafer. For example, this liquid process is a cleaning process for removing particles and/or contaminants deposited on a semiconductor wafer.
2. Description of the Related Art
In the process of manufacturing semiconductor devices or flat panel display devices (FPD), liquid processes are frequently used, in which a process liquid is supplied onto a target substrate, such as a semiconductor wafer or glass substrate. For example, processes of this kind encompass a cleaning process for removing particles and/or contaminants deposited on a substrate, and a coating process for applying a photo-resist liquid or development liquid in a photolithography stage.
As a liquid processing apparatus used for this purpose, the following apparatus is known. Specifically, a substrate, such as a semiconductor wafer, is held on a spin chuck, and a process liquid is supplied onto the front surface or front and back surfaces of the wafer, while the wafer is rotated. Consequently, a liquid film is formed on the front surface or front and back surfaces of the wafer, thereby performing a process.
In general, an apparatus of this kind is arranged to supply a process liquid onto the center of a wafer, and rotate the wafer to spread the process liquid outward, thereby forming a liquid film and throwing off the process liquid. A surrounding member, such as a cup, is disposed around the wafer to guide downward the process liquid thrown off from the wafer, so that the process liquid is swiftly drained. However, where a cup or the like is used, part of the process liquid may bounce back to the wafer as mist, and generate defects thereon, such as water marks and/or particles.
As a technique for preventing this problem, Jpn. Pat. Appln. KOKAI Publication No. 8-1064 discloses a technique which utilizes a process liquid receiving member to be rotated integratedly with rotary support means that rotates along with a substrate held thereon in a horizontal state. The process liquid receiving member receives a process liquid scattered around the substrate, and guides the process liquid outward to collect it. According to this publication, the process liquid receiving member includes a horizontal eaves portion, an inclined guide portion for guiding the process liquid outward and downward, a horizontal guide portion for guiding the process liquid outward in the horizontal direction, and a wall portion extending upward in the vertical direction, in this order from the substrate side. With this arrangement, the process liquid is guided into a narrow space to prevent mist from bouncing back onto the substrate, while the process liquid is drained from a drain port formed at a corner of the process receiving member. The process liquid is then discharged through grooves extending outward within a spacer disposed around the process liquid receiving member.
However, in the case of the technique disclosed in Jpn. Pat. Appln. KOKAI Publication No. 8-1064, the process liquid is guided into a narrow space around the substrate by the process liquid receiving member that rotates along with the substrate. Accordingly, the spacer portion around the substrate needs to be larger and increases the foot print of the apparatus. Further, it is necessary to exhaust gas along with drainage; which requires a mechanism for separating exhaust gas and drainage on the downstream side.